1. Field of the Invention
The present invention relates generally to an ignition control device for an internal combustion piston engine. More particularly, an ignition module having a stock appearance and cooperative with stock magnetos, distributors and coils enables maximum torque and power of the engine while simultaneously controlling a maximum revolution rate.
2. Description of the Related Art
Many drivers of collector cars such as stock antique and classic cars desire to protect, and where possible, improve the performance of their vehicles in an unobtrusive manner, most preferably maintaining the stock appearance not only of the body of the vehicle, but also of the engine compartment as well. Of particular interest to the present disclosure is the setting of maximum engine RPM (Rotations Per Minute) limits.
Unfortunately, and for a variety of reasons, an engine may be turned too quickly. For exemplary purposes only, and not limiting the present disclosure thereto, slip during acceleration, a slipping or blown clutch, a missed gear, failure to engage the clutch before fully opening the throttle, component failure such as a transmission failure, carelessness, and other such factors can lead to excessive engine RPMs. This can lead to engine failure, and may even result in an explosion or flying debris that can endanger bystanders. The aforementioned and other events that can lead to excessive RPMs can be further compounded by already high RPMs such as frequently occur during a race or upon traversing inconsistent or unpredictable surfaces such as ice or snow-packed roadways.
Typical stock ignition systems deliver electrical charge to engine spark plugs at energy levels well below component tolerances. Such stock ignition systems also do not usually provide over-rev protection. As a result, the operation and performance of the engine is compromised.
Recognizing a need for improved ignition systems, early pioneers developed a variety of electronic ignition systems that could provide improved control over the ignition spark. Exemplary of these are U.S. Pat. Nos. 4,052,967 by Colling et al, entitled “Digital electronic ignition spark timing system” and 4,790,280 by Umehara et al, entitled “Ignition apparatus”, the contents and teachings of each which are incorporated herein in entirety.
One popular approach to an electronic ignition is the capacitive discharge ignition (CDI) system. Exemplary are U.S. Pat. Nos. 4,046,125 by Mackie, entitled “Capacitive discharge ignition system”; 4,538,586 by Miller, entitled “Capacitive discharge ignition with long spark duration”; 4,620,521 by Henderson et al, entitled “Modular, programmable high energy ignition system”; 5,526,785 by Masters, entitled “Electronic ignition system”; 5,531,206 by Kitson et al, entitled “Capacitative discharge ignition system for internal combustion engines”; and 6,196,208 by Masters, entitled “Digital ignition”, the contents and teachings of each which are incorporated herein in entirety. One feature of these CDI systems is the ability to store energy in the capacitor and release that energy at desired times, assisting with the generation of an intense spark within the combustion chamber.
An additional development in electronic ignition systems is the incorporation of a computing device to programmably control spark. For the purposes of the present disclosure, the terms microprocessor, microcontroller, computer, computing device, CPU, and any other terms for electronic devices that permit software or programmed control over the system will be understood to be equivalent. Exemplary patents that illustrate computing devices within an ignition system, the contents and teachings of each which will be understood to be incorporated herein by reference in entirety, include: U.S. Pat. No. 4,558,673 by Mackie, entitled “Electronic ignition system for internal combustion engines”; U.S. Pat. No. 4,776,311 by Venieres et al, entitled “Process and device for limiting the running speed of an internal combustion engine with electronic ignition”; U.S. Pat. No. 4,883,033 by Hosoe et al, entitled “Ignition timing control system for internal combustion engines”; U.S. Pat. No. 4,895,120 by Tobinaga et al, entitled “Ignition control system for an internal combustion engine”; U.S. Pat. No. 5,131,367 by Aoki et al, entitled “Method for controlling ignition timing of internal combustion engine and apparatus therefor”; U.S. Pat. No. 5,138,995 by Erhard, entitled “Ignition process, arrangement and apparatus for internal combustion engines with a magneto”; 5,445,121 by Kai, entitled “Engine operational control unit”; U.S. Pat. No. 6,205,395 by Young et al, entitled “Ignition system and method of programming an ignition system”; U.S. Pat. No. 6,272,428 by Heath et al, entitled “Method and system for engine ignition for timing controlled on a per cylinder basis”; U.S. Pat. No. 6,484,692 by Umemoto et al, entitled “Ignition control system”; U.S. Pat. No. 6,915,777 by Fukushima et al, entitled “Control system for general-purpose engine”; and U.S. Pat. No. 7,040,282 by Andersson et al, entitled “Independent timing retard for engine speed limiting”.
Recognizing the particular importance of rev limiting, some inventors have designed rev limiting circuitry that will operate in association with an ignition system, for exemplary purposes to disable selected sparks, thereby selectively preventing combustion from occurring within one or more cylinders during a crankshaft revolution. Exemplary patents, the contents and teachings of each which will be understood to be incorporated herein by reference in entirety, include: U.S. Pat. No. 4,594,978 by Kanno, entitled “Over-revolution preventing apparatus for internal combustion engines”; U.S. Pat. No. 6,192,859 by LeFevre, entitled “Low cost, temperature stable, analog circuit RPM limiter”; U.S. Pat. No. 6,964,258 by Gudgeon et al, entitled “Engine revolution limiter”; and U.S. Pat. No. 7,050,899 by Masters et al, entitled “Slew rate revlimiter”.
Additional patents and published applications, the contents and teachings of each which will be understood to be incorporated herein in entirety, include: U.S. Pat. No. 3,601,103 by Swiden, entitled “Engine-condition-responsive cutoff apparatus”; U.S. Pat. No. 4,393,833 by Mann et al, entitled “Device for the control of the traveling speed of a motor vehicle”; U.S. Pat. No. 4,403,970 by Dretzka et al, entitled “Marine propulsion unit having ignition interruption means to assist transmission shifting”; U.S. Pat. No. 4,572,150 by Foster, entitled “Engine including means for retarding sparking operation to control engine overspeed”; U.S. Pat. No. 4,583,613 by Nakayama, entitled “Three wheel motorcycle with reverse mechanism”; U.S. Pat. No. 4,606,315 by Tobinaga et al, entitled “Ignition control system for an internal combustion engine”; U.S. Pat. No. 4,672,941 by Yamagata, entitled “Ignition system”; U.S. Pat. No. 4,697,560 by Umehara, entitled “Rotating speed control apparatus for an internal combustion engine”; U.S. Pat. No. 4,735,187 by Kato, entitled “Ignition system for internal combustion engines”; U.S. Pat. No. 4,858,585 by Remmers, entitled “Electronically assisted engine starting means”; U.S. Pat. No. 4,951,624 by Hirano, entitled “Ignition control for an engine to prevent overheating and backfiring”; U.S. Pat. No. 4,964,385 by Staerzl, entitled “Engine overspeed control”; U.S. Pat. No. 5,027,770 by Yano et al, entitled “Ignition controller”; U.S. Pat. No. 5,058,550 by Nagano et al, entitled “Method for determining the control values of a multicylinder internal combustion engine and apparatus therefor”; U.S. Pat. No. 5,070,840 by Kanno et al, entitled “Ignition system for marine propulsion unit”; U.S. Pat. No. 5,085,191 by Okuda, entitled “Tachometer signal generating device”; U.S. Pat. No. 5,090,383 by Demizu et al, entitled “Ignition timing control apparatus for an internal combustion engine”; U.S. Pat. No. 5,113,821 by Fukui et al, entitled “Vehicle speed governor”; U.S. Pat. No. 5,133,318 by Yokotani et al, entitled “After-burning preventive ignition apparatus for an internal combustion engine”; U.S. Pat. No. 5,133,319 by Ikeda et al, entitled “Engine speed control apparatus”; U.S. Pat. No. 5,138,996 by Fiorenza, entitled “Microprocessor-based engine speed limiter”; U.S. Pat. No. 5,511,526 by Hamburg et al, entitled “Engine air/fuel control with adaptive learning”; U.S. Pat. No. 6,758,189 by Uraki et al, entitled “Engine revolution control apparatus having overspeed governing capability”; U.S. Pat. No. 6,871,132 by Olsen et al, entitled “Engine limiter for powered vehicles”; U.S. Pat. No. 6,938,609 by Kustosch, entitled “Method and device for controlling the drive unit of a motor vehicle”; EP0501746 by Nagano et al, entitled “Altitude determination system and engine control system using the same.”; EP0618359 by Werner, entitled “Ignition system with device to limit revolutions and stabilise idling for a combustion engine.”; EP0693625 by Mizuno et al, entitled “An ignition timing control device for an engine”; EP0866222 by Inagaki, entitled “Ignition timing control system for industrial engines”; EP1167730 by Kanamaru et al, entitled “Device for controlling rotational speed of internal combustion engine”; EP1179672 by Ogawa et al, entitled “Control system and method for internal combustion engine.”; and EP1288493 by Ohno et al, entitled “Ignition timing control system and method, and engine control unit for internal combustion engine”.
In addition to the foregoing, Webster's New Universal Unabridged Dictionary, Second Edition copyright 1983, is incorporated herein by reference in entirety for the definitions of words and terms used herein.
In spite of the substantial development that has occurred in this field, there remains a need for a device that minimizes the likelihood of over-revving of an engine and which is most preferably incorporated directly into an existing ignition module package outline. This is particularly true in the case of collector cars, such as stock antique and classic cars, where cars are commonly judged not just on performance, but also on the maintenance of original or stock appearance.